Saigo Tsugiyori built an earthen-walled fortification in the Myodaiji
area of Okazaki, near the present castle in 1455. Matsudaira Kiyoyasu
, after gaining control of the area in 1524, demolished the old
fortification and built
Okazaki CastleOkazaki Castle on its present location. His
famous grandson Matsudaira Motoyasu (later named
Tokugawa IeyasuTokugawa Ieyasu ) was
born here on December 16, 1542. The Matsudaira were defeated by the
Imagawa clan in 1549, and Ieyasu was taken to
Sunpu Castle as a
hostage. Following the defeat of the Imagawa at the Battle of
Okehazama , Ieyasu regained possession of the castle in 1560 and left
his eldest son
Matsudaira NobuyasuMatsudaira Nobuyasu in charge when he moved to
Hamamatsu Castle in 1570. After
Oda NobunagaOda Nobunaga ordered Nobuyasu’s
death in 1579, the
Honda clan served as castellans. Following the
relocation of the Tokugawa to
EdoEdo after the Battle of Odawara by
Toyotomi HideyoshiToyotomi Hideyoshi , the castle was given to Tanaka Yoshimasa , who
substantially improved on its fortifications, expanded the castle town
and developed
Okazaki-juku on the Tōkaidō .

The current donjon was reconstructed in 1959 to boost local tourism.
In 2006, it was proclaimed one of the 100 Fine Castles of
JapanJapan . The
ferroconcrete structure has three roofs and five interior floors, and
contains exhibits of artifacts from the original castle, Japanese
swords , armor and dioramas illustrating local history. The Main Gate
of the castle was reconstructed in 1993, and the east corner yagura in
2010.

In 2007, construction work near the castle revealed stonework from
the castle’s outer baileys, lending evidence to the claim that
Okazaki CastleOkazaki Castle was once the fourth largest in Japan.

The area around the castle is now a park, with a museum dedicated to
the life of
Tokugawa IeyasuTokugawa Ieyasu and the Mikawa samurai , teahouses, a Noh
theater, a small clock tower with traditional karakuri puppets, and an
impressive main gate. The park is also renowned as a famous site for
viewing cherry blossoms , wisteria and azalea .